Aircraft propeller



Dec. 22,. 1942.

E, w. VOSE AIRCRAFT PROPELLER Filed Nov. '5, 1958 2 Sheets-Sheet l 1 q- E INVENTOR v Edwin W. 11056. BY'

71w 9% J ATTORNEYS Patented Dec.t22, 1942 j UNITED STATES PATENT; oF ica Edwin W. Vose; Orange, N. *J., assignor ol' thirtyeight and two-tenths per cent to the Estate of Henry D. Walbridge, deceased, late of New York,N.Y. I I H ApplicationNovember 5, 1938; Serial No. 238,987'

6 Claims. l-(cl. rid-16s) This inventionrelates to improvements inaircraft propellers and has for a main object the provision of a variable pitch propeller in which the pitch of its blades is automatically varied so as to maintain the motor which drives thepropeller at its most efilcient speed at'varying speeds of an aircraft-propelled thereby.

Another object of the invention is the provisionof an improved centrifugally operable vari-' able pitch propeller including simple mechanism for varying the pitch in accordance with the speed of rotation, said mechanism also including" means independentof the speed for changing said pitch. y

A further object of the invention is the provision in an aircraft propeller of novelmeans for- Figure 4 is an elevation, partly. in section, :01

the hub portion of the propeller blade support; showing details of the mechanism for varying the pitch of the propellers;

Figure 5is a sectional viewshowing the action of the centrifugal weights} Figure 6'isa fragmentary view, partly in sec- Figure '7 is a view similar to Figurej6, w ith the'j j exception that impeller blades for impelling cooling air are fixedly mounted'in the wheel-like sup; porting structure;

Figure 8 is a sectional elevation, similar to Figure 7, except that the impeller blades are shown .as' mounted pn themropeller' blade shafts so'as to vary their pitch in accordance with the varia supporting the blades of the propeller'on a driving motor. x h Another object of the invention is the provision in an aircraft propeller structure, of a zone about the center of the propeller in which cooling air is admitted to the driving motor.

v Still another object of the invention is the blades which furnish cooling airto the driving motor.

' tion of the pitch 'of 'the propeller blades; and

Figure 9 is afface view of a portion of the arrangement shown in Figure 8.

'A' support generally designatedby the numeral consists of arim member 2|, a hub member 22 and a plurality of spokes 23 which together form a wheel-like structure. The hub 22 has a 7 provision in an aircraft propeller of azone about the center of the propeller carrying impeller A further object of the invention is the provision'in an aircraft propeller of a wheel-like structure carrying bearings in its hub and bearings in line therewith in its rim forjournalling shafts carrying the propeller blades, and the further provision of a centrifugally controlled extend from their tips'to rim 2|.

mechanism for varying the pitch of saidblades.

Another object of the invention is the provision in avariable pitch aircraft propeller structure of a wheel-like supporting structure for the shafts of the blades having a hub and a rim conjointly -J0urnall-ing shafts carrying said blades, the provision of a streamlined casingsupported on said wheel-like structure, said streamlined casing.

matchingthe easing of the motor and having a central opening to permit cooling air to pass to the motor. r

Other objects will be apparent to those skilled in the art. y 1 Referring to the drawings which illustrate one embodiment of the invention:

Figure 1 is a front elevation of the improved aircraft propeller;

new and V Figure 2 is a side-elevation of the new propeller Q and its relation to a cowling enclosing the motor Figure 3 is a detailed view, partly in section, showing one method of mounting the propeller blade shafts; I

.hollow'24 extending therein from the front side as viewedin Figure 1, andhas a rearwardly extending portion or hub extension '25 which be seen in Figure 4. The shaft 26 of the motor carries the hub 22 the latter being secured thereto by suitable keyways, not shown, and retained on'said shaft; by means of the nut 21 suitably locked so as not to be loosened by vibration.

The propeller blades 28 are foreshortened and g a point clearingthe 7 Each propeller blade-28 is provided with a shaft 29 the center line of whichis preferably in line with the face of the blade.

The shaft 29 may berigidly secured to the blade'28 in any suitable manner, for example, by screwing the threaded end of theshaft 30 into the blade and then securing the same by means ofarivet 3|.

The'rim' 2| WhiChf'iS substantially spaced apart from the hub 22 carries a plurality of bearings for supporting "the outer'ends of the propeller.

shafts. 'One method of supporting the bearings in'the rim is illustrated in Figure 3. A hole 32 M in the rim 2l clears the shaft 29. The'hole 32 is counter-bored from inside the rim of thediameter of the bearing. The counter-bored hole is designated by the numeral 33 and a suitable bearing 34 which may be a roller bearing, fits into the counter-bored hole and fits on the shaft 29. A cup-like member 35 fits the outer diameter of the bearing 34 and may be secured to the rim 2| by means of rivets 36. Extending downwardly the shaft 29..

clearance hole .40 formed therein clearing the from the pinion 38. Reinforcing sector 41 has a tionary member 42 may be secured against rota- The rotatable portion'44 of the thrust bearing 43 of the shaft Z3 in any suitable manner and may threaded "end '41" of the Shaft; 12811 From this structure it may be seen that the shaftsjflcarrying the Propeller blades 28'are journalled in bear.-

structure 20. The outer. bearing 34 takes care of thela'teralthrust and theinner bearing 43 takes '-care of.. theflon il udlnal thrust due to the cen- .blade. 7 Although poundtypes. v

A flange 48 having a hub 49 journalledon the hub extension is provided with a'double throw annular thrust bearing"5fl. 'The thrust, bearing 50 may be secured to the hub by means of an annular ring 5| which may be screwed'on to the hub and permanentlyfriveted on after assembly.

may] be connected toa manual control, not shown, by mechanism including rods 54 and 55. The

ofthehub22. i

A plurality of weights 5 8, oneof which is shown in detailf'inFigure 5, are each carried on a lever shaft 60 supported by suitable lugs one ofwhich annular portion 22 of the hub 22. Each lever 59 lever portions 62 act against the ends of the bars shown inF'igure 5. I Y

Abar 63 is slidably journalled inholes B4, 65, formed in the webs 66 and 5]. The bar 63 has teeth 61 formed therein meshing with the pinion 38, The;bar 63, as above stated, is slidably jourpropeller speeds up the weights 58 fly out and the shown inFigure 5, and due to the fact that the bar 63 is secured to the flange 48, the movement The annular portion-22 of the 1111522 has;

portion of the shaft 23 extending'downwardly' hole formed therein matching the clearance hole 40 and this member 4l when positioned withinlthe hub 22 forms a reinforcing backing. for the sta tionary member 42 of the thrust bearing 43. Station within the hub 22 in any suitablemannen;

may be secured in fixed relation to the lower end he; maintained in said fixed relation. by means of nut 4 5 and a.,lock' nut 46 screwed on to the,"-

"theixthrus'tbearings 34 and 43 are shown'assiniple roller thrust bearings, itis obvi-T ousthat various types of special thrust bearings may be employed whether they besingleor com 7 A portion 50F'o'f thethrust bearing 50 may be. provided with extending. rods 52 and 53 which 7 V flange 48 carries a plurality of bars 56 which form working fits with openings formed i l-the'web 51 v is provided with anextending" arm 52 adapted to act against the end of the bar 56 so. that asthe propeller speeds up the weights 58' fly out and they 56 and thereby move the flange 48 to the right as.

nailed in the webs 66 and-51, and has one end" thereof secured to .theflange 48 so that as-the' from the bearing 34 shown in Figure 3; the Shaft; -29 tapers slightly and hasa shoulderli'ormed I therein adjacent to-the hub 31 of the pinion 38. Y

A suitable-keyway 39 maintains the pinion {38. i in fixed relation to the shaft 29 and suitable means, not shown in the drawing, may be pro vided for securing the pinion 38 positively'toQ to cause rotate, thereby changing the pitch of the blades.

.In the embodiment hereinshown and described,

'the' propeller blade shaft to thereare fourpro'peller blades and, therefore,

there are four' bars-f3 carrying racks B'L'each I being associated witha pinion 38 on the respective propeller blade shafts 29.

was-the horse-power of aircraft motors is being i inereased, larger propellersare'required for these -motors. However, in the prior art the practical limit for the number of blades in an aircraft propeller appears to be three blades; therefore, in order to properly load the motor, it would appear that withpropellers of the prior art the only,

' thingleft'to do is'to increase the dianieterof the propeller. Wherithe diameter of the propeller is increased, "the areas between the bladesiare increased, .therebyproviding space in which other blades could properl'y function, but the nature of 'ings spaced apart from each .other'the distance between the hub and the rim of the wheel-like ofthe propeller in direct proportion to the intrii'usal effect of thehigh y rotating p peller creaseof the power ofthemotor; Iii-other words,

-prop e11 rf of the prior art is such that extra blades may ot be addedwithout undue complications or the use of any desired number of blades is facilitated Twithout complicatingthe automatic control feature or the general structure; therefore, the newaridimproved propeller,- due to this important feature iwill permitthe-use of larger. and more powerful motors without'increasing the diameter as the propeller becomes larger in diameter,

if, as and when the same are developed. In order that the weights 58 return to their normal positions when the propeller is stopped, or returned to their normal positions; when the.

propeller .is' slowed down, suitable, springs, one of Y which is shown in Figure 4 and designatedbythe numerallfl, are provided; The spring 68 has one end secured tothe bar atthe point, andthe other end secured to the eye 10 of an eye-bolt;

and a suitable nut 12 is provided for adjusting the tension of the spring 68. The purpose in having the springs adjustable is in order that thepro-v peller when'the same is mounted on an engine shaft may be properly tuned to the engine in order to make the combination of the propeller'and the 59, each lever being pivotally mounted on a pivot is designated by the numeral! carried on the,

leverportions 62 act against the ends of the bars 58, thereby moving the flange48 tothe right, as-

of the latter causes the rack teeth 61 on the barengine an eflicientlyoperable unit. The spring resistance is set so that the pitch angle of the propeller blade changes at the proper points of speed of the engine rotation. Th'ese springs, through the medium of the bars B3,,urge the flange 43 to the left, as viewed in Figure 4, and this urge is in turn transmitted to the weights 58' through the medium of'the bars 56 and thearms 62. Although the springs 68 are shown as associated The flangesor webs 51 and 66 have their adjacent faces shouldered to form a support for. a

closure member 13 which maybe made in any suitable manner. and secured to the webs in any. suitable manner for completely enclosing the weights 58 and the active portions of the bars 56 and 63.. The shafts 29 pass through openings formed in the closure member I3 and felt pack- 2,306,096 ing rings '14 are provided between each shaft and the closure member 13 to prevent egress of lubricant orthe ingress of dust or other foreign matter.

A dome-shaped hub shield "l closes the projecting ends of the bar 63 and also encloses the inner thrust bearing 43 to pr'otectthem from dust, dirt and other foreign matter. Thi shield peller blades and due to" the absence of blade portions in active areas near the hub, the new and improved propeller herein described performs with a minimum of noise.

The path of the air leading to the motor when the plane is in motion is via the opening 19 and defined between the interior surface of the cowling 11 .and the exterior surface of the shield 15.

In cases where it is necessary'for the plane to taxi out to a position before taking off-and this is particularly true with sea-planesthe amount of air which passes over the motor, due to the blades have their 48, the bars, the racks B1, andthe-pinions 38.

The shaft 29 in rotating the propeller blades 28 to change the pitch to an efficient pitch, also 3 moves the impeller blades to a maximum pitch position neutral to the air'stream which is desirable because the motion of the aircraftwhile flying through the air causes suflicient air to pass into the opening 19 and thence about the motor,

and because substantially no power is used to drive the impeller blades when the aircraft is in Although the invention ha been disclosed and described in connection with the specific details of preferred embodiments thereof, it must be'understood that such details are shown by way'of example only and are not w .tive of the invention except in so far as set forth intended to be limitain the appended claims. 7 H

Whatis claimed is T 1. In an aircraft propeller, a hub having a tion adapted for attachment tp a driving motor 7 and a hollow portion adjacent to said first porradially from said hub, a propeller blade,

tion, a plurality of parallel flanges extending a shaft secured to said blade, a bearing for said shaft supported in said hub, a second bearing for said slow taxi motior of the plane with the wind, is

not sufiicient to cool the motor below the danger point. This dii'liculty is eliminated in the arrangement shown in Figures 7 to 9.

Referring now to Figure '7, a plurality of im-' peller-blades, one of which is designated by the numeral 80, are provided for furnishing a forced draft of air to the motor. The impeller blade 80 has a lug 8| formed at one end thereof which may be secured to a lug extension 82 carried by or formed integral with the rim 2|, by any suitable means, for example, by means of a rivet or rivets 83. The lower end of the impeller blade 80 is also provided with a lug 84 which may be secured to a lug extension 85 carried by or formed integral with the web 66 by means of'a rivet or rivets 86.

Although it may be preferable to provide one impeller blade for each propeller blade 28, it is obvious that as many or as few impeller blades 80 may be used in accordance with the type of work in which the new and improved propeller is used. The pitch of the impeller blade should preferably be steeper than that of the propeller blade so that when the propeller blade is at a minimum pitch, the impeller blade will be at an efiicient pitch for supplying air to the motor.

In the embodiment shown in Figures 8 and 9, the propeller blade shafts 29 each carry an impeller blade' so that the pitch of the impeller blades vary in a definit ratio with the pitch of the propeller. blades. In order to accomplish this, the propeller blades, one of which is illustrated in Figures 8 and 9, and designated by the numeral 81, is provided with a rib 88 of suitable form and having formed therein a hole fitting the shaft 29. The impeller blade 81 may be secured to the shaft 29 in any suitable manner, for example by means of rivets 89.. The pitch relation between the propeller and the impeller blades is such that when the propeller is rotating at a minimum pitch, the impeller'blades are at a pitch suitable to supply cooling air to the motor at an eificient 1 ture having a hub,

rate. As the propeller speeds up, the propeller shaft carried in a supporting member in parallel and spaced relation with said first bearing, said bearings forming. pivotal supports for said shaft, a pinion secured to said shaft and positioned between said bearings, a rack slidably J'ournaled-in said flanges and having teeth meshing with said pinion, a plate member slidably supported adjacent to one of said flanges and adapted to be moved on an axis coinciding with the axis of said hub, said rack being connected to and adapted to be moved axially by said plate member, speedresponsive means for moving said plate along its axis and thereby tending to change the pitch of said blade by rotating said shaft through the medium of said rack and pinion, resilient means yieldably resisting the movement of said plate for preventing the variation of the pitch of said blade until a predetermined speed of rotation has i been attained by said propeller.

2. In an aircraft including an engine, a propeller driven by said engine including a rotatively adjustable blade, a shaft secured to and having its center line in line with one face ofsaid blade, a hub mounted on said shaped member larger in diameter than and surrounding said hub, a plurality of. spokes holding said ring shaped member rigidly in concentric relation to said hub, bearing means in said hub and in said ring shaped member forming spaced supports for said shaft the axis of said engine, centrifugal apparatus associated with said shaft for increasing the pitch of said blade, mechanism yieldably urgingsaid blade toward its minimum pitch position and for holding said blade minimum pitch position until a. predetermined speed of said engine is attained, a plate member movable axially with respect to said means, connections between said plate-and said mechanism, and manually controlled means for moving said plate and independently changing the pitch of said-blade.

3. In an aircraft propeller, a wheel-like strucfor attachment to a driving motor and a hollow portion adjacent to said first portion, an annular of spokes for rim-like portion and a plurality porengine, an annular ring along a radial line cutting against movement. from its a portion of which is adapted rigidly, supporting relation to said;

saidjblade s and of thrust bearings for each shaft comprising an [of said rackshaving adjustable blade, a

blades, a shaft a 7 associated. shafts together, a set axial, thrust bearing means supported in ,said hub and radial thrust bearing means supported 1 in said rim,a pinion foreach shaft secured thereto in a position between said thrust, bearing means, a rack for each of said pinions slidably supported by said huband adaptedto'be moved along a line parallel to the axis ofsaid hub, each r '2,aoe,o9 e g r r I position until a predetermined speed ofv saidem gine is attained. 1 V

5. In an aircraft propellenfa hub structure, an

said rim-like portion in rigid hub, a, plurality of propeller; ,j foreach blade,means securing V I annulus in concentric'spaced relation to's'aid hub I structure, a plurality of spokes rigidly supporting said annulus on saidhub, a plurality of blades,

teeth meshing with one I of said pinions, an axially'slidable member common to and infixed relation with all of saidracks, speed-responsive means for moving said member along its axis and adapted through the medium of said racks and said ,pinions to change the pitch of said bladesby rotating said shafts, and resillent means yieldably resisting the movement of said member for preventing a variation of the pitch of said blade until a predetermined speed of rotation has been attained by? said propeller,

4. Inan aircraft including an engine, a propeller driven by said engine including a rotatively said hub for pivotally supporting said shaft at its inner end, an annular member substantially largerin diameter than andsurrounding said hub, a plurality of spokes supporting said mem 'ber aboutsaid hub a bearing in said annular 'member-also supporting said-shaft,'both said1 bearings'being in allgnment and'radially spaced blade against movement from its minimum pitch 26 shaft secured to said blade, a y hollow hub carried on said engine, a bearing in each of said bladeshaving a supporting shaft,

said spokes being angularly disposed with respect a tov said shafts and greater in number than said shafts, aplur'ality of sets of bearings forrotatably supporting said shafts, each-set including a bearing carried in said hub structure anda 1 second bearing in-alignment therewith carried in said annulusstructure whereby said blades may 7 be adjusted rotatably by rheansofsaid shafts,

mechanism between said hublstructure and said ,annulus' for increasing the --pltchof said'blades,

said mechanism includingmeansrotatably en--v gaging said shafts, and means'associatedwith said mechanism, for yieldablyresisting the rotatio'n of said shafts and the increase of the pitch of saidblades until the speed of rotation of said propeller reaches a predetermined value.

6. In an aircraft propeller, a wheel-like structure includinga hub, portion and a rim portion a with spokes-therebetween, for rigidly supporting the latter on said hub portion, a propeller blade,

v said blade having a shaft secured thereto to form a supporttherefona bearing for said'shaft carried in said hub portion, a' second bearing for said shaft carried in radial alignment with said first bearing and angular with the axis of said I hub portion by saidrim portion,'a speed-responsive mechanism supported on said hub portion and positioned between said hub portion and said rim portion for rotating said shaft to increase the pitch of said blade, and adjustable resilient means associated with said mechanism for yieldably resisting the action of said mechanism until a desired speed of rotation of said propeller is attained.

EDWIN VJ. VOSE. 

